Voltage regulator tube



May 22, 1956 F. c. TODD ETAL VOLTAGE REGULATOR TUBE Filed Nov. 29, 1951 INVENTORS FRANCIS C. TODD FIG. 2

ELMER C. LUSK I a" we United States Patent O "ice VOLTAGE REGULATOR TUBE Francis C. Todd and Elmer C. Lusk, Columbus, Ohio,

assignors to the United States of America as represented by the Secretary of the Army Application November 29, 1951, Serial No. 258,934

16 Claims. (Cl. 313--214) This invention relates to electron discharge devices and more particularly to gas filled devices of the voltage regulator type.

The object of this invention is to provide an electron discharge device having a greatly increased regulation. Prior voltage regulator devices have produced current ranges in the order of to 40 milliarnperes for a plate voltage variation of from 1 to 5 volts. The Within described device yields a current range of approximately to 460 milliamperes over the same range of plate voltage variation.

A further object of this invention is to provide a highly eflicient cathode structure for use in an electron discharge device.

Other objects of this invention will appear in the following description and appended claims, reference being had to the appended drawings wherein Fig. l is a side view of a complete electron discharge device according to this invention and Fig. 2 is another side view of the same device taken in a plane perpendicular to the plane of Fig. 1. I

Figs. 1 and 2 show an airtight, gas filled, envelope 10 (broken away) through which leads 12, 14, 16 and 18 are passed in such manner that the envelopes seal remains unbroken and so that the leads are held rigidly by the envelope. Envelope 10 contains an inert gas. Leads 12, 14, 16 and 18 are rigidly constructed so that they support the electrodes to which they are connected. Lead 12 is connected to and supports anode or collector electrode 20. Lead 14, by means of flanges 21 and 23, is connected to and supports both inner cylinder 22 and outer cylinder 24 of emitting electrode or cathode 26. Leads 16 and 18 are separately connected to flanges 25 and 27 at the other ends of cathode cylinders 22 and 24, respectively.

In the operation of a device according to this invention, a positive voltage with respect to hollow cathode 26 is applied to the anode 20 through the lead 12, which causes a discharge to strike from the anode 20 to the hollow cathode 26. A very intense illumination appears in the field free gap between the cathode cylinders 22 and 24. Said illumination differs in intensity and area in accordance with the current drawn by the tube, becoming dimmer and smaller as current lessens and growing progressively larger and brighter as current increases. The increase in area covered by the illumination as tube current increases causes the illumination to extend further into the region between the cathode cylinders during periods of increased conductivity. During such periods of high conductivity, the center of the glow region near the edge of the cathode cylinders becomes very hot, causing rapid deterioration of the cylinder walls; consequently, the intense glow region should not be allowed to extend over more than one quarter of the cylinder circumference. Such limiting may be accomplished by any means known to the art, such as: the use of a limiting series impedance.

As the illuminated region between the cathode cylin- 2,747,125 Patented May 22, 1956 ders is an efiicient source of electrons for conduction current, the tube current can be varied, over a wide range with little variation in voltage. Production of electrons in the glow region is due to a hollow cathode eifect, the simple explanation of which is that some electrons drawn from a cathode cylinder member traverse the space between the two cylindrical members of the cathode and impinge on the opposite cathode cylinder member, producing more electrons by secondary emission. As electron density builds up, ionization takes place on the surrounding gas and the 'y-processes (electron emission from the cathode by positive-ion bombardment, by metastableion bombardment or by the incidence of photons) become operative in the production of electrons.

As would be expected from the manner by which electrons are made available at the cathode of a device according to this invention, the physical configuration of said cathode is the predominant factor influencing electron production. Best results were found when a spacing of ,030 to .060 inch Was utilized between cathode cylinders and the outside cylinder was one inch in diameter and onehalf inch in length. Other tube constants, materials, and production techniques such as the use of a getter conform to standard practice.

It will be noted that when the cathode cylinder members are connected as shown and described, a conduction heating current can be made to flow in parallel through the inner and outer cylinders or it can be made to flow through the inner and outer cylinders in opposite directions with the cylinders connected in series. When the current flows in opposite directions through the inner and outer cylinders, the magnetic field, in the glow region, that arises from the conduction current is greatly reduced, thereby reducing hysteresis, because the current will displace itself in the metal so as to reduce the energy in the magnetic field and because the phase opposition of the currents produces opposing magnetic fields which cancel. The conduction heating current is applied through leads 14, 16 and 18 only during the conditioning of the device in order to reduce hysteresis effects. It is not necessary to condition the device, since it will condition itself during normal operation. During normal operation, and when the tube is not to be conditioned, leads 16 and 18 are not necessary and are connected to lead 14 or may be omitted.

Obvious modifications of the device as shown are to provide separate electrode supports in place of the rigid leads herein described and to connect the leads directly to the cathode cylinders without benefit of the flanged connecting connecting edges shown. However, these departures from the device shown are immaterial to the devices function.

What is claimed is:

1. In an electron discharge device the combination comprising an envelope; an inert gas within said envelope; an electron collecting electrode; and means to provide a hollow, intensely illuminated cathode region which serves an electron emitting source, said means comprising two metallic sheets circularly and concentrically disposed about said collecting electrode to form cylinders; a first current carrying lead electrically connected to said collecting electrode; a second current carrying lead having a common electrical connection to one end of. each of the said metallic sheets; a third current carrying lead electrically connected to the other end or" the inner sheet and a fourth current carrying lead electrically connected to the other end of the outer sheet.

2. In an electron discharge device as defined in claim 1 an electron emitting electrode whose inner and outer sheets are spaced between .030 and .060 inch from one another.

3. In a glow discharge device, an envelope having 4. An electron discharge device comprising an envelope containing an inert gas; an electron collector electrode; and a hollow cathode comprising a first electron emitting electrode at least partially surrounding said collector electrode, a second electron emitting electrode at least partially surrounding and parallel to said first electron emitting electrode, said electron emitting electrodes being in confronting relationship with each other, said first and second electrodes defining an interaction space therebetween to provide a highly ionized, luminous region which serves as an electron source, and means coupled between said electron emitting electrodes for maintaining them at the same potential.

5. An electron discharge device according to claim 4, wherein said first and second electron emitting electrodes are spaced concentrically about said collector electrode.

6. An electron discharge device according to claim 4, wherein said electron emitting electrodes are cylindrical in shape.

7. An electron discharge device according to claim 4, wherein said means comprises a current carrying lead connected to both of said electron emitting electrodes.

8. An electron discharge device according to claim 4, further including first and second current carrying leads respectively connected to said first and second electron emitting electrodes.

9. An electron discharge device according to claim 4, wherein said electron emitting electrodes are cylindrical in shape and spaced concentrically about said collector electrode.

10. An electron discharge device, according to claim 9, wherein the first electron emitting electrode is spaced 0.030 to 0.060 inch from said second electron emitting electrode.

11. An electron discharge device according to claim 9, wherein the length of said collector electrode is greater than the axial length of said electron emitting electrodes.

12. An electron discharge device comprising an envelope containing an inert gas; an electron collector electrode; a hollow cathode comprising a first cylindrical electron emitting electrode disposed concentrically about said electron collector electrode, and a second cylindrical electron emitting electrode disposed concentrically about said first electron emitting electrode, said first and second electron emitting electrodes defining an interaction space to provide a highly ionized, luminous region which serves as an electron source, said second electron emitting electrode being spaced 0.030 to 0.060 inch from said first electron emitting electrode, the outermost of said electron emitting electrodes having a diameter approximately equal to 1 inch; a first current carrying lead electrically connected to one end of said first electron emitting electrode; a second current carrying lead electrically connected to one end of said second electron emitting electrode; a third current carrying lead being electrically connected to the other end of each of said first and second electron emitting electrodes for maintaining them at the same potential; and a fourth current carrying lead electrically connected to said collector electrode.

13. An electron discharge device comprising an envelope containing an inert gas; an anode; and a cathode composed of a pair of spaced, parallel electron emitting electrodes in confronting relationship with each other, said electrodes defining an interaction space therebetween to provide a highly ionized luminous region which serves as an additional source of electrons, and means for maintaining said electron emitting electrodes at the same potential.

14. An electron discharge device as set forth in claim 13, wherein said electrodes are approximately the same length.

15. A gaseous discharge device comprising an envelope containing an inert gas, an anode, and means to provide a cathode region of intense glow, said means comprising a pair of electron emitting electrodes spaced from said anode and from each other, said electrodes being in confronting relationship with each other and forming an interaction space therebetween in which said glow is formed.

16. A device as set forth in claim 15, wherein the distance between said electrodes is .030 to .060 inch.

References Cited in the file of this patent UNITED STATES PATENTS Rentschler Jan. 3, 1933 Simons Feb. 19, 1935 OTHER REFERENCES 

